Hydraulic reciprocating motor



Sept 29 1964 c. w. oLsoN 3,150,566

HYDRAULIC RECIPROCATING MOTOR Filed Oct. 25, 1962 2 Sheets-Sheet l nu, IIL MW 4 4l 4 mman/MMI# w M zar//l Y i wn .h a QV W f m7 Sept. 29, 1964 c. w. oLsoN HYDRAULIC RECIPROCATING MOTOR 2 Sheets-Sheet 2 Filed Oct. 23, 1962 United States Patent O 50,566 HYDRAULEC REQIPROCATING MTUR Clyde W. Gison, Glenwood, Minn. nnen oet. z3, 1962, ser. N6. 232,433 3 Claims. (Cl. 91-282) This invention relates generally to iiuid pressure operated motors, and more particularly to reciprocatory motors and control means therefor.

An important object of my invention is the provision of a reciprocatory fluid pressure operated motor having novel direction reversing valve means operatively associated therewith for .automatically reversing the direction of movement of the reciprocatory element of the motor.

Another object of my invention is the provision of a motor as set forth, which requires no added valve mechanism for starting or reversing the operation of the motor.

Another object of my invention is the provision of novel valve construction which prevents nonfunction of the motor when the same is stopped at a so-called dead center position of the reversing valve thereof.

Still another object of my invention is the provision of a motor and reversing valve structure which eliminates the necessity for check valves, springs, and external means for operating the reversing valve.

Another object of my invention is the provision of a fluid pressure operated reciprocatory motor which is relatively simple and inexpensive to produce, which is highly efiicient in operation, and which is rugged in construction and durable in use.

The above, and still further highly important objects -and advantages of my invention will become apparent from the following detailed specification, appended claims, and attached drawings. Referring to the drawings, which illustrate the invention, and in which like reference characters indicate like parts throughout the several views:

FIG. 1 is a View in side elevation of a uid pressure operated reciprocatory motor produced in accordance with my invention;

FIG. 2 `is a view in end elevation, as seen from the right with respect to FIG. l;

FIG. 3 is a transverse section taken substantially on the line 3 3 of FIG. 1;

FIG. 4 is la transverse section taken on the line 4-4 of FIG. 1;

FIG. 5 is an enlarged longitudinal section taken on the line 5--5 of FIG. 2; and

FIG. 6 is an enlarged fragmentary section taken on the irregular line 6-6 of FIG. 2.

In the preferred embodiment of my invention illustrated, a main body 1, preferably made from cast iron or Ithe like, is shown as being provided with -an apertured boss 2 and threaded holes 3, by means of which the body or housing 1 may be mounted on a suitable supporting istriuotulre, not shown. The body 1 is longitudinally bored to provide a power cylinder 4, one end of which is defined by a cylindrical plug element or the like 5 anchored in place by a retaining nut or the like 6 screwthreaded into the adjacent end of the body 1. The other end of the cylinder 4 is defined by a tubular member 7 that engages a shoulder 8, and which is anchored in place by a tubular packing nut 9 and packing material 10. The plug element 5 defines a control cylinder 11, the tubular member 7 defining a second control cylinder 12, the control cylinders 11 and 12 being axially aligned with the power cylinder 4. As shown in FIG. 5, the plug element 5 .and tubular member 7 are channeled in the exterior surfaces thereof for reception of conventional O- rings 13 and 14 respectively, for sealing purposes.

Mounted for axial sliding movements in the power cylinder 4 is `a power piston 15 formed at its opposite ends to provide relatively large kand relatively small piston porice tions 16 and 17 respectively, the piston portions 16 and 17 being loosely slidably receivable in the control cylinders 12 and 11 respectively during reciprocal movements of the power piston 15. An elongated piston rod 18 extends axially outwardly from the piston portion 16 through the packing 10 and packing nut 9, the outer end 19 of the piston rod 18 being adapted to be operatively coupled to a reciprocatory tool, not shown. As shown in FIG. 5, the power piston 15 with its control piston portions 16 and 17, and the piston rod 18 are all axially aligned, the packing nut 9 being provided at its outer end with a conventional sealing ring 2Q for the purpose of preventing foreign material from entering the packing nut 9.

The body or housing 1 is further bored to define a reversing valve cylinder 21 the opposite ends of which are defined by a pair of identical end plugs 22 and 23 having axial recesses which provide auxiliary cylinders 24 and 25 respectively, the auxiliary cylinders Z4 and 25 being axially aligned with the reversing valve cylinder 21. As shown in FIGS. 5 and 6, the end plugs 22 and 23 are securely anchored in place by retaining nuts 26 screw-threaded into the opposite ends of the housing or body 1. Like the plug element 5, and tubular member 7, the end plugs 22 and Z3 are channeled for reception of O- rings 27 to seal the valve cylinder 21 against leakage of fluid to the exterior of the body 1.

Axially slidably mounted in the reversing valve cylinder 21 is a spool-like reversing valve element or piston 2S comprising a central piston portion 29, axially aligned reduced neck portions 30 and 31 at opposite ends of the piston portion 29, iianges 32 and 33, and diametrically reduced auxiliary piston elements 34 and 35 that are axially movable and in respective ones of the auxiliary cylinders 24 and 25 during axial movement of the reversing valve element 28 within the reversing valve cylinder 21. The piston portion 29, flanges 32 and 33, and auxiliary pistons 34 and 35 closely slidably engage the wall portions of their respective cylinders 21, 24 and 25 so as to have substantially sealing engagement therewith. The opposite ends of the piston portion 29, the neck portions 3@ and 31, and flanges 32 and 33 define annular chambers or passages 36 and 37 that shift longitudinally of the body or housing 1 with shifting movements of the reversing element 2S. As shown in FIGS. 3 and 6, the reversing valve element 23 is provided with a transverse passage 38 and an axial passage 39 which extends from the passage 3S to the auxiliary cylinder 25, for a purpose which will hereinafter be described.

The main body or housing 1 denes an inlet 4b that is screw-threaded to receive a conduit fitting, not shown, whereby the inlet may be connected to a source of fiuid under pressure. An inlet passage 41 extends inwardly from the inlet 4d and has thereto a plurality of inlet branch passages 42, 43 and 44. The branch passage 42 terminates in a circumferential channel 45 in the wall of the reversing valve cylinder 21 and disposed centrally between the ends of the cylinder 21. The branch passages 43 and 44 terminate in circumferential channels 46 and 47 respectively in the Wall of the cylinder 21 in axially spaced relation to the channel 45, see FIGS. 5 and 6. The body 1 further defines an outlet 48 similar to the inlet 40, which communicates with a longitudinally extending outlet passage 49 that communicates with the cylinder 21 by means of branch outlet passages 50 and 51 and circumferential channels 52 and 53 respectively at opposite end portions` of the cylinder 21. A pair of transfer passages 54 and 55 extend between opposite end portions of the power cylinder 4 and respective circumferential channels 56 and 57 in the wall of the reversing valve cylinder 21, the channel 56 being disposed axially between the channels 28 and 52,

and the channel 57 ybeing disposed axially between the channels 47 and 53. The body 1 is further provided with a pair of control passages 5S and 59, the former of which communicates with the control cylinder 11 by means of a circumferential channel 6) and radial passages 61 in the plug element 5, and with the auxiliary cylinder 24 by means of a circumferential channel 62 and radial passages 63 in the end plug 22. The control passage 59 communicates with the control cylinder 12 by means of a circumferential channel 64 in the body 1 and radial passages 65 in the tubular member 7, and with the auxiliary cylinder 25 through a circumferential channel 66 outwardly of the end plug 23 and radial passages 67 in the end plug 26.

With the power piston and reversing valve element 28 positioned as shown in FIGS. 5 and 6, fluid under pressure introduced to the inlet 4t) is conducted to the power cylinder 4 adjacent the plug element 5 through the branch passage 43, annular passageway 36 and transfer passage 54 whereby to impart movement to the power piston 15 and parts associated therewith in a direction toward the tubular member 7. Because the power cylinder 4 adjacent the plug element 5 is under pressure, and because of the loose fit between the control piston 17 and control cylinder 11, the auxiliary cylinder 24 is maintained under pressure to prevent movement of the reversing valve element 28 to the right with respect to FIGS. 5 and 6. During movement of the power piston 15 and parts carried thereby in an outward direction to the left with respect to FIG. 5, fluid in the cylinder 4 between the power piston 15 and tubular member 7 is moved through the transfer passage 55, `annular passage 37 and branch passage 51 to the outlet 48. Should a pressure drop occur in the control cylinder 11 and auxiliary cylinder 24, during movement of the control piston 17 outwardly from the control cylinder 11, such a pressure drop will, at most, be sufricient to cause only a slight movement of the reversing valve auxiliary piston 34 into the auxiliary cylinder 24; and, as soon as the control piston 17 leaves the control cylinder 11, pressure of fluid in the adjacent end of the power cylinder 4 will cause the reversing valve element 28 to move back to its extreme position of FIGS. 5 and 6.

As the power piston 15 approaches the limit of its movement in an outward direction or toward the left with respect to FIG. 5, the control piston portion 16 enters the control cylinder 12, causing uid under pressure to be introduced to the auxiliary cylinder through the passages 65, channels 64, passage 59, channel 66 and passages 67, to impart movement to the reversing valve element 2S to the right with respect to FIGS. 5 and 6 until the flange 32 engages the adjacent end of the end plug 22. Fluid under pressure then flows inwardly through the branch passage 44, channel 47, annular passageway 37, transfer passage 55 and into the end portion of the power cylinder 4 adjacent the tubular member 7 to cause the power piston 15 to move from the left t0 the right with respect to FIG. 5. Fluid in the power cylinder 4 at the opposite end of the power piston 15 flows outwardly through the transfer passage 54, channel 56, annular passageway 36, and branch and outlet passages 50 and 49 respectively to the outlet 4S. Then, as the piston 15 approaches the plug element 5, the control piston 17 enters the control cylinder 11 to cause an increase in fluid pressure in the control cylinder 11 and the auxiliary cylinder 24 communicating therewith, to move the reversing valve element 28 to the left with respect to FIGS. 5 and 6 to the position shown therein. Thus, a cycle of operation is completed, and a new cycle begins, the speed of reciprocatory movement of the power piston 15 and piston rod 18 being dependent upon the volume of fiuid introduced to the inlet 40.

As sometimes occurs, when the piston rod 1S is operatively coupled to a tamping device, the tamping head of the device engages the wori: and stops movement of the power piston 15 at a point wherein the reversing valve 23 is moved substantially one half of its limit of movement from the right to the left with respect to FIGS. 5 and 6. Normally, at this point the reversing valve element 28 is at a dead center position in the reversing cylinder 21 and, without the passages 3S and 39, the motor would be stalled. However, in the event that the reversing valve element 28 cornes to a stop midway between its limits of reciprocatory movement, fluid under pressure from the inlet 4G moves inwardly through the branch passage 42 to the channel 45, from whence it enters the passage 33 and 39 and flows to the auxiliary cylinder 25, thus moving the valve element 2S to the right with respect to FIGS. 5 and 6 to cause movement to be imparted to the power piston 15 towards the right with respect to FIG. 5.

My reciprocating motor has been thoroughly tested and found to be completely satisfactory for the accomplishment of the objectives set forth; and, while I have shown and described a commercial embodiment thereof, it will be understood that the same is capable of modification without departure from the spirit and scope of the invention, as defined in the claims.

What I claim is:

1. In a reciprocating motor,

(a) means defining a power cylinder and control cylinders at opposite ends of said power cylinder in axial alignment therewith,

(b) a power piston axially movable in said power cylinder and having control pistons at opposite ends thereof receivable in respective ones of said control cylinders responsive to axial movement of said power piston in opposite directions,

(c) an axial piston rod movable with said power and control pistons and extending through one of said control cylinders and an opening in said means for attachment to a reciprocatory tool,

(d) said means defining a valve chamber and auxiliary chambers at opposed portions of said valve chamber,

(e) and a reversing valve element movable alternately in opposite directions in said valve chamber and having auxiliary valve elements for corresponding movements in said auxiliary chambers,

(j) said means defining an inlet for connection to a source of fluid pressure, an outlet, inlet passages from said inlet to spaced portions of said valve chamber, transfer passages from other spaced portions of said valve chamber to opposite end portions of said power cylinder, a pair of control passages between said control cylinders and respective ones of said auxiliary chambers, `and outlet passages from said outlet to spaced portions of said valve chamber spaced from said inlet and transfer passages,

(g) said reversing valve element defining passageways connecting one of said transfer passages alternately to one of said inlet and outlet passages and the other of said transfer passages alternately to others of said inlet and outlet passages responsive to movements of said reversing valve in opposite directions,

(h) said reversing valve being movable in said opposite directions responsive to movements of respective ones of said control pistons into their respective control cylinders,

(i) said control pistons having diameters sufficiently less than their respective control cylinders to permit limited fiow of fluid therebetween during movement of said control pistons in their respective control cylinders.

2. In a reciprocating motor,

(a) means defining a power cylinder and control cylinders at opposite ends of said power cylinder in axial `alignment therewith,

(b) a power piston axially movable in said power cylinder and having control pistons at opposite ends thereof receivable in respective ones of said control cylinders responsive to axial movement of said power piston in opposite directions,

(c) an axial piston rod movable with said pov/er and control pistons and extending through one of said control cylinders and an opening in said means for attachment to a reciprocatory tool,

(d) said means defining a reversing valve cylinder and diametrically reduced auxiliary cylinders at opposite ends of said reversing valve cylinder in axial alignment therewith,

(e) and a reversing valve piston axially movable in said reversing valve cylinder and having diametrically reduced auxiliary pistons at opposite ends thereof axially movable in respective ones of said auxiliary cylinders responsive to axial movements of said reversing valve piston in opposite directions,

(f) said means deiining an inlet for connection to a source of fluid pressure, an outlet, inlet passages from said inlet to axially spaced portions of said reversing valve cylinder, transfer passages from other axially spaced portions of said reversing valve cylinder to opposite end portions of said power cylinder, a pair of control passages between said control cylinder and respective ones of said auxiliary charnbers, and outlet passages from said outlet to axially spaced portions of said valve chamber in axially spaced relationship to said inlet and transfer passages,

(g) said reversing valve piston defining passageways connecting one of said transfer passages alternately to one of said inlet and outlet passages and the other of said transfer passages alternately to others of said inlet and outlet passages responsive to movements of said reversing valve piston in opposite directions,

(h) said reversing valve piston being movable in said opposite directions responsive to movement of respective ones of said control pistons into their respective control cylinders,

(i) said control pistons having diameters suliiciently less than their respective control cylinders to permit limited flow of fluid therebetween during movement of said control pistons in their respective control cylinders.

3. In a reciprocating motor,

(a) a housing having a bore defining a power cylinder,

(b) means dening a relatively large diameter control cylinder at one end of said power cylinder and a relatively small diameter control cylinder at the other end of said power cylinder and axially aligned therewith,

(c) a power piston axially movable in said power cylinder and having relatively large and relatively small diameter control piston portions at opposite ends thereof axially movable into respective ones of said control cylinders responsive to axial movements of said power piston in opposite directions,

(d) a piston rod projecting axially from said relatively large diameter control piston portion and extending through an axial opening and said means defining the relatively large diameter control cylinder for `attachment to a reciprocatory tool,

(e) said housing having a bore dening a reversing valve cylinder,

(f) means at opposite ends of said reversing valve cylinder defining diametrically reduced auxiliary cylinders axially aligned with said reversing valve cylinder,

(g) and a reversing valve piston axially movable in said reversing valve cylinder and having diametrically reduced auxiliary piston portions at its opposite ends axially movable therewith in respective ones of said auxiliary cylinders,

(h) said housing defining, an inlet for connection to a source of fluid pressure, an outlet, inlet passages from said outlet to axially spaced portions of said reversing valve cylinder, outlet passages from said outlet to opposite end portions of said reversing valve cylinder in axially outwardly spaced relation to said inlet passages, and transfer passages extending from axially spaced portions of said reversing valve cylinder to opposite end portions of said power cylinder,

(i) said housing and said means cooperating to define control passages connecting each of said control cylinders with a respective one of said auxiliary cylinders,

(j) said reversing valve piston dening passageways connecting one of said transfer passages alternately to one of said inlet and outlet passages and the other of said transfer passages alternately to others of said inlet yand outlet passages responsive to movements of said reversing valve piston in opposite directions,

(k) said reversing valve being movable in said opposite directions responsive to movement of respective ones of said control pistons into their respective control cylinders,

(l) said control pistons having diameters suiiiciently less than their respective control cylinders to permit limited iiow of iiuid therebetween during movement of said control pistons in their respective control cylinders,

(m) said reversing valve having a passageway independently connecting one of said inlet passages to the auxiliary cylinder connected to said rela-tively large diameter control cylinder at one position of movement of said reversing valve piston.

References Cited in the file of this patent UNITED STATES PATENTS 526,149 Farley Sept. 18, 1894 2,336,847 Couty Dec. 14, 1943 2,379,483 Hopgood July 3, 1945 2,932,175 May Apr. l2, 1960 2,970,579 Paris Feb. 7, 1961 

1. IN A RECIPROCATING MOTOR, (A) MEANS DEFINING A POWER CYLINDER AND CONTROL CYLINDERS AT OPPOSITE ENDS OF SAID POWER CYLINDER IN AXIAL ALIGNMENT THEREWITH, (B) A POWER PISTON AXIALLY MOVABLE IN SAID POWER CYLINDER AND HAVING CONTROL PISTONS AT OPPOSITE ENDS THEREOF RECEIVABLE IN RESPECTIVE ONES OF SAID CONTROL CYLINDERS RESPONSIVE TO AXIAL MOVEMENT OF SAID POWER PISTON IN OPPOSITE DIRECTIONS, (C) AN AXIAL PISTON ROD MOVABLE WITH SAID POWER AND CONTROL PISTONS AND EXTENDING THROUGH ONE OF SAID CONTROL CYLINDERS AND AN OPENING IN SAID MEANS FOR ATTACHMENT TO A RECIPROCATORY TOOL, (D) SAID MEANS DEFINING A VALVE CHAMBER AND AUXILIARY CHAMBERS AT OPPOSED PORTIONS OF SAID VALVE CHAMBER, (E) AND A REVERSING VALVE ELEMENT MOVABLE ALTERNATELY IN OPPOSITE DIRECTIONS IN SAID VALVE CHAMBER AND HAVING AUXILIARY VALVE ELEMENTS FOR CORRESPONDING MOVEMENTS IN SAID AUXILIARY CHAMBERS, (F) SAID MEANS DEFINING AN INLET FOR CONNECTION TO A SOURCE OF FLUID PRESSURE, AN OUTLET, INLET PASSAGES FROM SAID INLET TO SPACED PORTIONS OF SAID VALVE CHAMBER, TRANSFER PASSAGES FROM OTHER SPACED PORTIONS OF SAID VALVE CHAMBER TO OPPOSITE END PORTIONS 